Even as U.S. and Iraqi forces consolidated gains in Fallujah and beat back smaller uprisings throughout the Sunni triangle, they began contemplating the challenge of persuading the Sunni minority that its best hopes lie in Iraqi elections, not insurgents.

U.S. officials said they hope the week-long assault on Fallujah, designed to take down insurgent strongholds, forces Sunnis to recognize that they can't hold territory in the face of overwhelming U.S. firepower and must participate in the political process for their own well-being.

It is unclear whether Sunnis, who dominated Saddam Hussein's Baath Party and benefited more than any other Iraqi group from his rule, agree with that argument. Sunni insurgents have countered the overwhelming assault on Fallujah with a surge in attacks in Mosul -- where insurgents quickly overran Iraqi police forces -- Ramadi and most recently, Baqubah, where 27 people were killed yesterday in fierce fighting. In the town of Buhriz, militants killed the local police chief. Americans responded by dropping two 500-pound precision-guided bombs on an insurgent position.

"The insurgents can strike where we're not strong, and don't have to hold the ground for long to win the headlines and the support of the uncommitted, especially if [they are] ruthless," said one senior military official. "This will be a long fight."

Before the U.S.-led offensive, negotiations between Iraq's interim government and a coalition of several leading Sunni groups seemed to be tentatively moving forward. The Sunnis suggested they might be willing to withdraw their support for the insurgency if the U.S. met a half-dozen conditions designed to assuage their concerns about elections scheduled for January.

"They were beginning to get down to how they could be sure the minimum Sunni demands would be met and the elections would be free and fair," said Larry Diamond, a professor at Stanford University in California who served as a senior official in the American occupation authority. "This is how civil wars end -- when people like this begin to sue for peace."

Senior U.S. officials in the Pentagon and Iraq are hopeful that the assault on Fallujah will give the U.S. more leverage with insurgents. As the elections set for January approach, Pentagon officials say, they believe that leverage will grow. "Once the Sunnis see the Shiites and Kurds taking part in the elections, the hope is they will start playing ball," said one Pentagon official.

These officials note that the death toll in Fallujah has been far lower than many Sunnis feared and that the attack has moved much more quickly than many in the U.S. and Iraq believed possible, largely because significant numbers of insurgents -- including leaders such as Abu Musab al-Zarqawi -- appear to have slipped out of the city before the long-planned assault. The interim government also has stood by the U.S. throughout the assault, a big change from April, when several members of the now-defunct Iraqi Governing Council threatened to resign over a planned U.S. offensive.

The assault did prompt the country's most prominent Sunni political party to withdraw from the interim government in protest last week, while a leading group of Sunni clerics called on Iraqis to boycott the elections. The Fallujah assault also seems to have emboldened insurgents in other parts of the country. The crumbling of Iraqi security forces in Mosul is "not a good news story," said one military official in the Pentagon.

A senior American official at the U.S. Embassy in Baghdad said the U.S. expected political repercussions from the assault but that concerns were outweighed by the risk of allowing Fallujah to remain an insurgent stronghold. "These guys are ticked off now, but we think they'll come back to the table after emotions cool a bit and they see that being part of the process is a better choice than trying to derail it through violence," the official said.

To move forward, both the U.S. and the interim government probably will need to set aside concerns about negotiating with representatives of groups that might have actively supported the insurgency with money, weapons and foot soldiers.

They also will likely have to accede to some of the Sunnis' demands. Before the Fallujah invasion, the coalition of Sunni groups negotiating with the U.S. insisted, among other things, on the repeal of laws barring former Baathists from elections, the confinement of U.S. forces to their bases for a month before Iraqis headed to the polls and the replacement of several members of Iraq's nascent electoral commission.